Apparatus for coating tablets with computer control

Abstract

A method and apparatus for coating medical tablets and pellets, for example, which are to be coated with a protective film or wherein an ingredient is to be added or the appearance of the material is to be improved wherein the various parameters which control the production rate which are determined by such variables as the spray rate, the temperature, the coating pan speed, the air flow, dew point, and composition of the spray material are used to calculate the optimum conditions for producing the coated tablets or pellets. The sensed parameters are supplied to a computer which controls the spray rate, the drum speed, the amount of heat and other factors so as to optimize and automatically control the apparatus and method for coating pellets and tablets.

We claim as our invention: 
     
       1. Apparatus for coating objects comprising, a machine with a rotating drum in which said objects to be coated are placed, drum driving means connected to said rotating drum, a spray head mounted in said rotating drum for supplying spray to said objects to be coated, air inlet means connected to said machine to supply inlet air to said drum, air outlet means connected to said machine to remove air from said drum, means for supplying spray to said spray head, a computer connected to supply inputs to control said drum driving means and said spray supplying means, and a plurality of sensors for detecting inlet air humidity, temperature and flow rate, drum air temperature and outlet air temperature connected to supply inputs to said inputs to said computer so that it can monitor and control said coating machine, and wherein said means for supplying spray to said spray head includes a fluid reservoir and a pump, said computer connected to control said pump and sensors for measuring pressure and quantity of said fluid supplied to said spray head supplying inputs to said computer so that said computer controls the spray head so as to the time of application of fluid, quantity of fluid applied, the rate of fluid applied to said objects, and time of drying. 
     
     
       2. Apparatus for coating objects according to claim 1 including a heat exchanger connected in said inlet air means and an inlet blower connected in said inlet air means and said computer connected to control said inlet blower. 
     
     
       3. Apparatus for coating objects according to claim 2 including sensors for detecting the temperature and humidity of inlet air before it passes said heat exchanger and said sensors supplying inputs to said computer. 
     
     
       4. Apparatus for coating objects according to claim 3 including a dehumidifier connected in said inlet air means. 
     
     
       5. Apparatus for coating objects according to claim 4 including first filter means through which said inlet air passes and a differential pressure sensor connected across said first filter and supplying an input to said computer. 
     
     
       6. Apparatus for coating objects according to claim 1 including an exhaust blower connected in said outlet air means and said computer connected to said exhaust blower to control it. 
     
     
       7. Apparatus for coating objects according to claim 6 including a second filter connected in said outlet air means and differential pressure sensing means connected across said second filter and supplying an input to said computer. 
     
     
       8. Apparatus for coating objects according to claim 1 including an air source connected to said spray head and said computer connected to control said air source and air pressure and quantity sensors connected to said air source and supplying inputs to said computer. 
     
     
       9. Apparatus for coating objects according to claim 1 including a printer connected to said Computer for providing a print out. 
     
     
       10. Apparatus for coating objects according to claim 1 including alarm means connected to said computer and actuated thereby if the conditions of the apparatus for coating are outside normal conditions or signal completion of coating process.